There are a variety of cutting devices in numerous applications including masonry, machining, metal cutting, glass cutting, wood cuffing and stone cutting, which can employ a chain, rotary blade or other cutting element. Saw chains employ a chain design and material components unique to the particular application. In many cases the chain and teeth of one saw have a design that cannot be used in a saw for a different application. Also, chain tooth materials necessary for one application such as masonry, are not well suited to other applications such as wood cutting.
In the timber industry, saw chains of chain saws and timber harvesters are designed to cut the wood of trees. The conditions of wood to be cut influence the choice of material that is used for the cutting teeth of the saw chain. For example, under normal wood cutting conditions, saw chains having steel teeth are used. However, when cutting trees in an area where there are nails, staples or other metal articles that may have been inserted into the trees such as in areas near old farmland, saw chains employ more costly carbide-brazed steel cutting teeth because they can cut through metal articles in the tree and through the wood without becoming excessively dull.
The teeth of all saw chains undergo expected wear. This is typically addressed by the time-consuming process of sharpening the teeth or changing-out the dull chain with a sharpened chain. This delay in cutting causes a costly decrease in productivity of the cutting operation.
Attempts have been made to employ removable inserts usually made of steel. These inserts have taken on various designs but, in general, have been unsuccessful and are not used widely if at all. U.S. Pat. No. 2,583,243 discloses a chain saw which employs removable teeth which are wedged into the slot of a head of a saw chain link. U.S. Pat. No. 2,852,048 discloses a saw chain with removable cutter teeth having a T-shaped recess which engages a T-shaped element on a cutting link body. U.S. Pat. No. 3,547,167 discloses a removable cutting sleeve which has an opening that receives a stud of the cutting link body.
The typical saw chain material of teeth used to cut wood is one-piece stamped and machined metal (e.g., steel) which is not formed at close tolerances using conventional machining techniques. Commercially available wood-cutting saw chain teeth are permanently affixed to the chain. In applications where there is a risk of cutting into a tree containing metal pieces, saw teeth may employ a carbide article soldered to the metal tooth. Despite superior physical properties of brazed carbide teeth compared to steel teeth, their use is reserved for particular settings because of the added cost of the carbide material and soldering process. The wood cutting industry could benefit from saw chains including removable cutting teeth made from a material that makes the design economically feasible with superior physical properties compared to conventional stamped teeth that are permanently affixed to the chain.